• V.F. Agekyan
  • E.V. Borisov
  • L.E. Vorobjev
  • G.A. Melentyev
  • H. Nykänen
  • L. Riuttanen
  • A.Y. Serov
  • S. Suihkonen
  • O. Svensk
  • N.G. Filisofov
  • V.A. Shalygin
  • L.A. Shelukhin
The optical and electrical properties of silicon-doped epitaxial gallium nitride layers grown on sapphire have been studied. The studies have been performed over a wide range of silicon concentrations on each side of the Mott transition. The critical concentrations of Si atoms corresponding to the formation of an impurity band in gallium nitride (∼2.5 × 1018 cm−3) and to the overlap of the impurity band with the conduction band (∼2 × 1019 cm−3) have been refined. The maximum of the photoluminescence spectrum shifts nonmonotonically with increasing doping level. This shift is determined by two factors: (1) an increase in the exchange interaction leading to a decrease in the energy gap width and (2) a change in the radiation mechanism as the donor concentration increases. The temperature dependence of the exciton luminescence with participating optical phonons has been studied. The energies of phonon-plasmon modes in GaN: Si layers with different silicon concentrations have been measured using Raman spectroscop
Original languageEnglish
Pages (from-to)787-793
JournalPhysics of the Solid State
Volume57
Issue number4
DOIs
StatePublished - 2015

ID: 4007068